package server;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;


import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import mapper.Context;
import mapper.Host;
import mapper.Mapper;
import mapper.Wrapper;
import service.Engine;
import service.Service;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**定义socket监听的端口号*/
    private int port = 8080;
    
    List<Service> serviceList = new ArrayList<>();


    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }


    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {
    	
    	// 加载webapp配置  初始化服务
    	loadServerConfiguration();

//        // 加载解析相关的配置，web.xml
//        loadServlet();


        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize =50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );
        

        for (Service service : serviceList) {
            ServerSocketProcessor serverSocketProcessor = new ServerSocketProcessor(service, threadPoolExecutor);
            serverSocketProcessor.start();
        }
        




        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        // 读取客户端发送的数据
//        ServerSocket serverSocket = new ServerSocket(port);
//        System.out.println("=====>>>Minicat start on port：" + port);

        /*while(true) {
            Socket socket = serverSocket.accept();
            // 有了socket，接收到请求，获取输出流
            OutputStream outputStream = socket.getOutputStream();
            String data = "Hello Minicat!";
            String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length) + data;
            outputStream.write(responseText.getBytes());
            socket.close();
        }*/


        /**
         * 完成Minicat 2.0版本
         * 需求：封装Request和Response对象，返回html静态资源文件
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            response.outputHtml(request.getUrl());
            socket.close();

        }*/


        /**
         * 完成Minicat 3.0版本
         * 需求：可以请求动态资源（Servlet）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            // 静态资源处理
            if(servletMap.get(request.getUrl()) == null) {
                response.outputHtml(request.getUrl());
            }else{
                // 动态资源servlet请求
                HttpServlet httpServlet = servletMap.get(request.getUrl());
                httpServlet.service(request,response);
            }

            socket.close();

        }
*/

        /*
            多线程改造（不使用线程池）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            requestProcessor.start();
        }*/



        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
       /* while(true) {

            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            //requestProcessor.start();
            threadPoolExecutor.execute(requestProcessor);
        }*/
        
    }


    private Map<String,HttpServlet> servletMap = new HashMap<String,HttpServlet>();

    /**
     * 加载解析web.xml，初始化Servlet
     */
    private void loadServlet() {
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("web.xml");
        SAXReader saxReader = new SAXReader();

        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();

            List<Element> selectNodes = rootElement.selectNodes("//servlet");
            for (int i = 0; i < selectNodes.size(); i++) {
                Element element =  selectNodes.get(i);
                // <servlet-name>lagou</servlet-name>
                Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                String servletName = servletnameElement.getStringValue();
                // <servlet-class>server.LagouServlet</servlet-class>
                Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                String servletClass = servletclassElement.getStringValue();


                // 根据servlet-name的值找到url-pattern
                Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                // /lagou
                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                servletMap.put(urlPattern, (HttpServlet) Class.forName(servletClass).newInstance());

            }



        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }
    
    private void loadServerConfiguration(){
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("server.xml");
        SAXReader saxReader = new SAXReader();
        try {
            Document document = saxReader.read(resourceAsStream);
            //根元素
            Element rootElement = document.getRootElement();
            List<Element> listService = rootElement.selectNodes("//Service");

            for (Element element : listService) {

                Engine engine = new Engine();
                List<Element> hostList = element.selectNodes("//Host");
                String port = element.element("Connector").attributeValue("port");

                Mapper mapper = new Mapper();
                for (Element elementHost : hostList) {
                    String hostName = elementHost.attributeValue("name");
                    String appBase = elementHost.attributeValue("appBase");
                    Host host = getHost(appBase);
                    mapper.setHostMap(hostName,host);
                }

                engine.setMapper(mapper);

                Service service = new Service();
                service.setEngine(engine);
                service.setPort(Integer.parseInt(port));

                serviceList.add(service);
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    
    private Host getHost(String appBase){
        Host host = new Host();
        File file = new File(appBase);
        if (file.exists() && file.isDirectory()) {
            File[] files = file.listFiles();
            for (File webApp : files) {
                String contextName = webApp.getName();
                String webAppPath = webApp.getPath();
                Context context = getContext(webAppPath);
                host.setContextMap(contextName,context);
            }
        }
        return host;
    }


    private Context getContext(String webAppPath){
        Context context = initContext(webAppPath);
        return context;
    }
    
    /**
     * 读取webapps
     * @param webAppPath
     * @return
     */
    public static Context initContext(String  webAppPath){
        String webXmlAbsolutePath = webAppPath+"/web.xml";
        System.out.println("开始加载Context");
        Context context = new Context(webAppPath);
        try {
            InputStream inputStream = new FileInputStream(new File(webXmlAbsolutePath));
            SAXReader saxReader = new SAXReader();
            Document document = saxReader.read(inputStream);
            //根元素
            Element rootElement = document.getRootElement();
            List<Element> selectNodes = rootElement.selectNodes("//servlet");

            for (int i = 0; i < selectNodes.size(); i++) {
                Element element = selectNodes.get(i);

                Element servletNameElement =(Element)element.selectSingleNode("servlet-name");
                String servletName = servletNameElement.getStringValue();
                Element servletClassElement =(Element)element.selectSingleNode("servlet-class");
                String servletClass = servletClassElement.getStringValue();

                Element servletMapping =(Element)rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']'");
                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                
                System.err.println("urlPattern"+urlPattern);

                Class<?> clas = findClass(webAppPath,servletClass);

                Wrapper wrapper = new Wrapper((HttpServlet) clas.getDeclaredConstructor().newInstance());

                context.setWrapperMap(urlPattern,wrapper);
            }

        }catch (Exception e){
            e.printStackTrace();
        }
        return context;
    }
    
    
    private static Class<?> findClass(String webAppPath,String name) throws ClassNotFoundException {
    	MyClassLoader myClassLoader = new MyClassLoader();
    	return myClassLoader.findClass(webAppPath, name);
    }


    
    



    /**
     * Minicat 的程序启动入口
     * @param args
     */
    public static void main(String[] args) {
        Bootstrap bootstrap = new Bootstrap();
        try {
            // 启动Minicat
            bootstrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
